British Law Enforcement Agencies Campaign to Use Biased Facial Recognition Technology

Law enforcement agencies across the UK effectively campaigned to use a face scanning system acknowledged as discriminatory against women, youths, and members of minority ethnic backgrounds, after complaining that a less biased version generated fewer potential suspects.

How the System Works

British police utilize the police national database (PND) to carry out searches using historical face recognition. This procedure entails comparing a reference photograph of a suspect against a repository of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This admission followed a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and women at much greater frequency than Caucasian males. The ministry said it “took steps on the findings”.

“This raises the issue of whether this technology only becomes useful if users tolerate discrimination in ethnicity and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to address the problem.

Senior officers were informed of the system's bias in September 2024. The government-ordered laboratory study concluded the system was had a higher probability to suggest incorrect matches for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a point where the bias was greatly diminished.

However, this decision was reversed the following month after forces complained that the adjusted system was generating a lower number of “investigative leads”. NPCC documents show the stricter setting cut the number of queries that yielded possible identifications from over half to a mere 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is now in operation, the recent NPL study discovered the system could generate false positives for women of Black heritage almost 100 times more frequently than for white women at specific configurations.

The Home Office commented on these results: “Our evaluation found that in a limited set of circumstances the software is more likely to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's confidence threshold, the police records state: “This adjustment greatly lessens the effect of discrimination across legally safeguarded attributes of race, age and gender but had a substantially detrimental effect on operational effectiveness”. The papers add that forces argued that “a previously useful tool now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month consultation on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has described the tool as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little consideration in equality strategy sessions of the technology deployment despite obvious cross-over with the strategy's goals.

“These revelations demonstrate yet again that the pledges to combat discrimination the police has made through the race action plan are failing to be integrated into wider practice. Our reports have warned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and poor data collection continue to exist.

“All deployment of facial recognition must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than compounds ethnic bias.”

Home Office Response

A government representative said: “The Home Office takes the conclusions of the study seriously and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled in the coming months and will be subject to further assessment.

“Our priority is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is human involvement in every step of the procedure and no arrest or charge would be pursued without specialist personnel meticulously examining the results.”